Light emitting diode package structure

ABSTRACT

A light emitting diode package structure includes a substrate, LED bare chips and a lens. The substrate has an upper surface, a lower surface and a side surface between the upper surface and the lower surface. The upper surface is provided with a circuit pattern. The side surface is provided with a groove. The LED bare chips are fixed on the upper surface and electrically connected with the circuit pattern. The lens covers the LED bare chips, the upper surface and the circuit pattern by an injection molding process so as to be inserted into the groove. With this arrangement, the connecting strength between the substrate and the lens can be enhanced, thereby achieving waterproof and anti-electrostatic effects. Further, material cost of the present invention is reduced greatly.

This application is a division application (DA) of U.S. patentapplication Ser. No. 13/084,947, filed on Apr. 12, 2011.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an illumination device, in particularto a light emitting diode package structure.

2. Description of Prior Art

Since light emitting diodes (referred to as “LED” hereinafter) areenergy-saving, they have become a new-generation light source forreplacing traditional bulbs. Currently, LEDs have been widely used inindoor or outdoor illumination.

A conventional light emitting diode package structure is proposed, inwhich an upper surface of a substrate is provided with an annulargroove. A LED chip is mounted on the surface of substrate on which theannular groove is formed. A binder made of silicon materials is filledinto the groove, and then a lens covers outside the LED chip. The bottomof the lens is embedded into the groove and combined therewith.

However, the conventional light emitting diode package structure merelyallows one LED chip to be mounted thereon. When a plurality of LED chipsare to be mounted on the same substrate, the steps of forming a grooveon the substrate, filling the binder in the groove and covering the lenshave to be performed for the LED chips respectively. As a result, themanufacturing time and cost cannot be reduced. On the other hand, insuch a package structure, the binder is used to connect the substrateand the lens. However, the lens is formed into a thin shell with a lessconnecting strength, so that the lens may be disconnected from thesubstrate easily. Further, the conventional package structure does nothave waterproof and anti-electrostatic effects, and thus really needs tobe improved.

SUMMARY OF THE INVENTION

The present invention is to provide a light emitting diode packagestructure, in which a lens is inserted into or engaged with a substrateto thereby enhance the connecting strength therebetween. Thus, thepresent invention has waterproof and anti-electrostatic effects.

The present invention is to provide a light emitting diode packagestructure, including a substrate, a plurality of LED bare chips and alens. The substrate has an upper surface, a lower surface and a sidesurface between the upper surface and the lower surface. The uppersurface is provided with a circuit pattern, and the side surface isprovided with a groove. The LED bare chips are fixed on the uppersurface and electrically connected with the circuit pattern. The lenscovers the LED bare chips, the upper surface and the circuit pattern bymeans of an injection molding process so as to be inserted into thegroove.

The present invention is to provide a light emitting diode packagestructure, including a substrate, a plurality of LED bare chips and alens. The substrate has an upper surface, a lower surface and a sidesurface between the upper surface and the lower surface. The uppersurface is provided with a circuit pattern, and the side surface isprovided with a flange. The LED bare chips are fixed on the uppersurface and electrically connected with the circuit pattern. The lenscovers the LED bare chips the upper surface and the circuit pattern bymeans of an injection molding process so as to be engaged with theflange.

The present invention has the following advantageous features. The firstlens covering the surface of the LED bare chip can be omitted, therebyreducing the material cost greatly.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a perspective view of the present invention showing respectivebare chips being mounted on the substrate;

FIG. 2 is an assembled cross-sectional view of FIG. 1;

FIG. 3 is an assembled cross-sectional view of the present inventionshowing the lens covering the respective bare chips;

FIG. 4 is a perspective view showing the external appearance of thepackage structure of the present invention; and

FIG. 5 is an assembled cross-sectional view showing another embodimentof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description and technical contents of the present inventionwill become apparent with the following detailed description accompaniedwith related drawings. It is noteworthy to point out that the drawingsis provided for the illustration purpose only, but not intended forlimiting the scope of the present invention.

Please refer to FIGS. 1 and 2. The present invention provides a lightemitting diode package structure including a substrate 10, a pluralityof LED bare chips 20 and a lens 30.

The substrate 10 is made of metallic materials having good heatconductivity such as aluminum, copper or alloys thereof. The substrate10 is formed into a capsule shape and has an upper surface 11, a lowersurface 12 and a side surface 13. The lower surface 12 is located belowthe upper surface 11. The side surface 13 is formed vertically betweenthe upper surface 11 and the lower surface 12. The upper surface 11 isprovided with a circuit pattern 111. Copper clad circuit on the circuitpattern 111 is combined with the upper surface 11 in an electricallyinsulating manner. The first and last ends of the circuit pattern 111are formed with an electrical conductive contact 112 respectively.Similarly, after the circuit pattern 111 is made completely, the circuitpattern 111 is fixedly bonded on the upper surface 11. The side surface13 is provided with an annular groove 131 surrounding the profile of thesubstrate 10. The cross section of the groove 131 may be formed into anyone of a rectangular shape, a trapezoid shape, a V shape, a semicircularshape, a dovetailed shape, a triangular shape and other suitable shapes.

The LED bare chips 20 are respectively arranged on the upper surface 11of the substrate 10 at intervals based on the traces of the circuitpattern 111. The electrodes (not shown) of the LED bare chip 20 areelectrically connected in series with the copper clad circuit of thecircuit pattern 111. In the present embodiment, although the respectiveLED bare chips 20 are electrically connected in series with each other,the electrical connection between the LED bare chips 20 is not limitedto a serial connection only, but other forms of electrical connectionsmay be used.

Please refer to FIGS. 3 and 4. After arranging the respective LED barechips 20 on the substrate 10, this combination of the LED bare chips 20and the substrate 10 are put into a pre-formed mold (not shown). Then,molten resin is injected into the mold in such a manner that a portionof the molten resin covers the LED bare chips 20, the upper surface 11of the substrate 10 and the circuit pattern 111, and the other portionof the molten resin flows along the inner walls of the mold to be filledinto the groove 131. After the molten resin is cured, a lens 30 isformed. A solid light-guiding post 31 is formed in the lens 30 above acorresponding LED bare chip 20. The light-guiding post 31 issubstantially formed into a conical shape. The top of the light-guidingpost 31 is formed into a light-converging protrusion 311 for convergingthe light, thereby increasing the light emitting efficiency. The outerperiphery of the light-guiding posts 31 is formed with an annular frame32.

Please refer to FIG. 5. In addition to the above embodiment, the lightemitting diode package structure of the present invention can be carriedout by another embodiment, in which the side surface 13 of the substrate10 is formed with an annular flange 14. After the molten resin isinjected to the mold, the molten resin covers the LED bare chips 20, theupper surface 11 of the substrate 10 and the circuit pattern 111, andthe other portion of the molten resin flows along the inner walls of themold to be engaged with the annular flange 14. After the molten resin iscured, a lens 30 is formed, and the connecting strength between the lens30 and the substrate 10 can be enhanced greatly.

What is claimed is:
 1. A light emitting diode package structure,including: a substrate (10) having an upper surface (11), a lowersurface (12) and a side surface (13) between the upper surface (11) andthe lower surface (12), the upper surface (11) being provided with acircuit pattern (111), and the side surface (13) being provided with aflange (14); a plurality of LED bare chips (20) fixed on the uppersurface (11) and electrically connected with the circuit pattern (111);and a lens (30) covering the LED bare chips (20), the upper surface (11)and the circuit pattern (111) by means of an injection molding processso as to be engaged with the flange (14).
 2. The light emitting diodepackage structure according to claim 1, wherein the substrate (10) is ametallic substrate.
 3. The light emitting diode package structureaccording to claim 2, wherein the circuit pattern (111) is combined onthe upper surface (11) of the metallic substrate (10) in an electricalinsulating manner.
 4. The light emitting diode package structureaccording to claim 2, wherein a first and a last ends of the circuitpattern (111) are formed with an electrical conducting contact (112)respectively.
 5. The light emitting diode package structure according toclaim 2, wherein the flange (14) is an annular flange surrounding aprofile of the substrate (10).
 6. The light emitting diode packagestructure according to claim 1, wherein a solid light-guiding post (31)is formed in the lens (30) above a corresponding LED bare chip (20), andthe light-guiding post (31) is formed into a conical shape.
 7. The Lightemitting diode package structure according to claim 6, wherein a top ofthe light-guiding post (31) is formed into a light-converging protrusion(311), and a periphery of the light-guiding posts (31) is formed with anannular frame (32).